A printing device for ejecting droplets of an electrically conductive fluid such as a molten metal is known. Such a device may be used for ejecting droplets of a fluid having a high temperature, such as a molten metal or a molten semiconductor.
An example of such a device is described in WO 2010/063576 A1. The device according to WO 2010/063576 A1 comprises a fluid chamber, adapted to contain the electrically conductive fluid and may be used for direct printing of molten metals. In WO 2010/063576 A1, it is described that droplets of the molten electrically conductive fluid are expelled through an orifice of the printing device by generating a Lorentz force in the electrically conductive fluid. Direct printing of molten electrically conductive fluids, such as molten metals may be employed for printing electronic circuits, for example.
However, often, electrically conductive fluids, such as molten metals, release a significant amount of vapor, even at temperatures slightly above the melting temperature. These vapors may be harmful. For example, these vapors may have a strong negative effect on the human health, in case these vapors are inhaled. Second, vapors that precipitate outside of a reservoir or outside of the print head may cause damage to equipment and cause pollution of the system. For example, precipitation of the electrically conductive fluid may hamper the process. The printing process takes place at elevated temperatures. Therefore, the electrically conductive fluid has to be heated. Often, this is done by inductive heating, wherein a induction heating coil is placed around a reservoir comprising the electrically conductive fluid. In case the vapor of the electrically conductive fluid precipitates between the induction heating coil and the reservoir, heating may be hindered and the printing process may be hampered. Moreover, evaporation of the electrically conductive fluid leads to loss of material. This is unwanted, especially if the electrically conductive fluid is an expensive material. Therefore, it is desirable to prevent the vapors of the electrically conductive fluid from escaping from the electrically conductive fluid material reservoir, such as a fluid chamber, into the environment.
It is an object of the invention to mitigate the above problems.